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460
Democritus Develops the Idea of Atoms
in 460 B.C,, Democritus wondered if when you break an object in half Over and over again, How many times witll you break the object until you can break it no further. Then he came to the decision that when it does end, it would be at the smalllest point ever, and decided to call it an atom. -
John Dalton Rediscovers Atoms
While doing an experiment, he noticed that there were little lumpy particles in chemicals. He didnty know how they were built, but he did know it was something fundamental. -
J.J. Thompson discovers electron
Thompson discovered electrons, and realized that they had a negative charge. That observation led him to belive that matter had a positive charge. Upon these findings, he made a replica of the atom. -
Albert Einstein and Light
Albert saw that the laight's quanta acted like particles. He decided to call them photons. -
Max Planck and Vibrating Atoms
Max had discovered that when you vibrate atoms strong enough, you can measure the energy in discrete units. He decided to call those packets of energy Quanta. -
Albert Einstein Writes His Paper
Albert wrote a paper about how light absorption can release electrons from atoms, which he called the photoelectric effect. In 1921 he recieved a nobel prize for his findings. -
Ernest Rutherford discovers the nucleus
In 1911, Ernest Rutherford decided to attack atoms with alpha rays because he wanted to examine the inside of the atoms. He also used Radium as the alpha particles and shinned them onto the atoms he put in gold foil. Behind the foil was a fluorescent screen where he could observe the alpha particles impact. When he did the experiment, some of the alpha particles went through the foil, Rutherford also found that the negative electrons orbited a positive center like the solar system. -
Niels Bohr makes a theory
His thery was that electrons do not spiral into the nucleus. He also came up with rules for what actually does happen.
1. Electrons can orbit only at certain allowed distances from the nucleus.
2. Atoms radiate energy when an electron jumps from a higher-energy orbit to a lower-energy orbit. Also, an atom absorbs energy when an electron gets boosted from a low-energy orbit to a high-energy orbit. -
Ruthford discovers protons
In 1919, the ruthford had found that the particles in the nucleus were discrete positive charges of matter. He used alpha particles of bullets, and he knocked hydrogen nuclei out of atoms of six elements called boron, fluorine, sodium, aluminum, phosphorus, an nitrogen. he decided to call them protons. He also found that the protons mass 1,836 times greater than the mass of the electron. -
They find flaws in Bohrs findings
Experiments showed that the spectral lines weren't correct when a magnetic field influenced the atoms. Therefor, Bohr and another scientist made a correct model showing that the way the electron orbits has different shapes. It also showed that the orbits could tilt when a magnetic force comes around. -
Louis de Broglie & Particles Of Matter
he thought idf light can exist as particles and waves, why couldnt particles also act like waves. In a model, he showed what matter waves would look and act like if the existed. -
Wolfgang Pauli Makes a Prediction
His prediction was that an electron should spin while orbiting the nucleus. It also says that the electrons can spin in 2 directions -
Werner heisenberg has a theory
His theory ( Called the Matrix Mechanics ) explained the behavior of atoms. It was based off of mathmatical quantities. -
Erin Schrodinger has an idea
his idea was " Why not go all the way with particle waves and try to form a model of that atom?" His idea was considered to work like a violin string, except the vibrations traveled in a circular motion. -
Edwin Schrodinger
Edwin had had a idea. His idea was "Why not go all the way with particle waves and try to form a model of the atom on that basis?" His idea was said to work like a violine sting, except going in a circle, not straight down.his wave mechanics did not question the makeup of waves but he had to call it something, so he called it psi. -
Max Born & Psi
He thought that Psi ( Schrodingers wave mechanics) resembled the waves of change. -
Heisenberg has another idea
His idea stated that no experiment can measure the position and movenent of a quantum particale. -
Paul Dirac
Paul had made a pridiction that there was a positive charged electron. It was not excepted at the time, but it was proved in 1932 by Carl Anderson -
Paul Dirac
He started the theory that says that all forces in the universe are carried by a quantum particle. -
James Chadwick Discovers the neutron
James had found that the neutron was a little bit heavier than the proton and had no charge. -
Werner Heisenburg
he concludeed that charged particles bounce photons of light between them. -
Hideki Yukawa
He had a sugestion that said that the exchange forces might describe the secure force between nucleons. -
quantum electrodynamics
In the 1940's, 3 scientists helped work on creating the quantum electrodynamics theory. -
Cecil F. Powell
He found another particle and called it the pion. -
More Particles
From 1947 to 1950's, scientist found more and more particles. -
scientist find something
They found that there were anti protons and anti neutrons, along with the excistence of anti electrons. -
Murray Gell-Mann and Yuval Ne'man
The two scienist created the eightfold way, a method for classifying all the known particles. -
Gell Man
He discovered the quarks. -
The findings of more Quarks.
Gell Man had found 3 quarks called up, down, and strange. But in 1974-1984, they found 3 more, and decided to call them Charm, Bottom ( also called beauty), and Top ( aka truth).
